In a 40 man operation (like Alterac Valley) there is a lot of information that I think is probably just bogging down the works. There are so many people in the run, and you simply don't care about so much stuff, that I think this could be simplified. If you did all of the following things together, you might see an FPS increase, still have the same functionality, and without quite so much clutter.

-Name Font Size could be much smaller, in it's place, increase the health bar and mana bar size
-take away the OOR message. The Fade In/Fade Out for in and out of range is plenty sufficient, especially since you don't generally care about the people. With 25 man raids being the most in raiding, the extra info on the is just extra.
-group # is only slightly useful, so I can see it staying, but it could be smaller
-you don't need an indication if people in your group are casting, it is PvP, everyone is casting.
-Don't need to see health #s or %s, simply looking at the bar is sufficient for that number of people.

I took a year off from WoW, and came back. So this is my first jump into nUI, so some of these suggestions might be from ignorance.